Cylinder Honing

Cylinder Service Centre undertakes cylinder honing to provide a finely finished highly accurate cylinder in a wide range of different materials such as:

  • all steels
  • non ferrous metals

Cylinder Service Centre have invested in one of the largest honing machines in the UK giving us the capacity to hone and manufacture tubes of up to 650mm diameter x 14 meters.

The honing process is highly flexible allowing Cylinder Service Centre to also produce:

  • out of round bores
  • tapered bores
  • bores with keyways and ports
  • bowed bores
  • tandem bores

This in-house capacity sets us aside from our competition and means we can provide fast, economic repair and the manufacture of bespoke cylinder tubes of all sizes.

It also means that we can manufacture odd sized cylinder tubes from scratch in our own premises therefore drastically reducing lead-times and associated costs.

The Cylinder Service Centre has the only in-house honing capability of this type in the North of England and the whole of Scotland.

Honing preparation and set-up

About the Honing Process

There are a number of different types of honing process, but at Cylinder Service Centre we use bore honing.

In simple terms, honing is a type of advanced grinding process. Although grinding and honing do differ in many respects, the objective of both processes is to achieve dimensional accuracy and a generally fine surface finish. Grinding usually involves an abrasive wheel moving at relatively high speeds normally along a line contact and this can result in a high impact shock to the metal with resultant surface finish implications. Honing uses a different approach making it more suitable for finer surface finishes and dimensional accuracy when dealing with cylinder bores.

The advantages of honing over a more conventional grinding process are:

  • The fineness of the finish
  • The configuration of the surface finish
  • The roundness of the cylinder.

The Fineness of the Finish

The fineness of the finish is achieved because the honing process is overall gentler than grinding. The process can be up to 40 times slower than grinding (15 -76 metre/min v 762 - 2900 metres/min for grinding) and does not suffer from the impact risks that we may have with grinding as there is constant contact between the tool and the cutting surface of the cylinder throughout the honing process.

This constant contact is achieved by a tool that holds stones that traverse with a motion that is like a helical motion. That is, it moves up, or down the cylinder as it turns. The tool also presses outwards, spring loaded to tolerate eccentricities in the circular motion. The constant change in the direction of movement means that imperfections on the cutting surface of the tool are not transferred to to the surface of the cylinder and so a fine finish is achieved.

The Configuration of the Surface Finish

Honing stones are man made assemblies of aluminium oxide or silicon carbide abrasive grits assembled into an abrasive block and bonded together with an an agent that can be baked to create a solid tool. The size of the tool unsurprisingly will depend upon the size of bore to be cut.

The movement of this stone within the cylinder as described above provides a fine finish, but with a cross hatch type pattern at a microscopic level. This pattern is ideal for holding microscopic levels of lubricant making it perfect for use in hydraulic cylinder applications.

The Roundness of the Cylinder.

The honing tool assembly is less rigid than a grinding tool even to the point where the circular motion has a degree of eccentricity. Intuitively, one would think that any sort of eccentricity in the circular motion would be a bad thing, but the honing process uses this to its advantage. The complex circular and reciprocal movement of the stones means that final circle of the bore hole is a sort of average and in effect this creates a cylinder that is as close to perfect as can be practicably achieved.

This means that (certainly in cylinder repair terms), the honing will be done first to provide a datum for other machining processes

Finally

If honing is a process at the core of hydraulic cylinder repair and manufacture, then it is also at the core of our business. Cylinder Service Centre offers exceptional honing expertise and we look forward to you contacting us to discuss your cylinder honing requirements in the not too distant future.